Theory of mind

I was watching a programme on chimps and they were saying how exciting it was that they could create an experiment that demonstrated chimps had theory of mind and that this made them like humans. hte problem is they have it backwards. we have proof that one species has theory of mind (humans) but we dont have proof that anyone else DOESNT have theory of mind thus it is nonsense to proove a chimp has it without first prooving everyone else DOESNT. So as opposed to going through this stupid charade where we slowly one by one prove chimps dolphins and crows have theory of mind we should be asuming it and waiting for proof otherwise (which is somewhat difficult because even some humans may have theory of mind but not use it in certain instances when causing harm to another person.